Show the world size in km²:

#if RUST
            double WorldKm = ConVar.Server.worldsize /1000.0;
            WorldKm = Math.Pow(WorldKm,2);
...
                .Replace("{server.worldsize.in.km}", WorldKm.ToString("00.00") + " km²")​

Use commas to separate the entity count by thousands (untested with 100k+):

.Replace("{server.entities}", BaseNetworkable.serverEntities.Count.ToString("#,##0"))

Thanks for a great plugin :)

To account for single and multi-digit numbers to the left of the decimal, use this code instead:

                .Replace("{server.worldsize.in.km}", WorldKm.ToString("#0.0#") + " km²")​

 

To call the calculated value, you'll use in the config's Status section:

"{server.worldsize.in.km} World"​